So after an oil change and carb adjustment, my 88cc xr50 has began a sudden ticking sound. The oil added was 20/50 motorcycle oil, which could possibly be too thick? Not sure why it would cause this sound. Here is a video of it...

After correcting the timing, it ran perfect for a few seconds then the ticking started again. Any help would be really appreciated....

motonphoto, on 18 July 2012 - 01:57 PM, said:

A couple of questions:
1.  What timing are you talking about?  I thought ignition timing wasn't adjustable.
2.  You say the ticking started again.  Was it doing it before?  If so, what made it go away?
3.  How's your valve clearance?
4.  What else did you do to the bike?  I might be inclined to retrace my steps, including any disassembly you did to see if something came loose.

I don't think 20W50 would be too thick.  The manual says it's good for temperatures of about 35F and up.  However, if you're still concerned, change it to 10W40.  It's cheap.  It could be purely coincidental that it happened with the oil change, but eliminates one variable that was changed just prior to the start of the ticking.

1. The timing chain that goes from the cam to the flywheel.
2. The ticking started suddenly after the oil change, and it was a simple oil change. About 5 minutes of riding, then the tick started. After pulling the t-chain sprocket and realigning the chain, i reassembled and started, and it idled for approx 5 seconds until the loud tick came back. It almost sounds like the piston hitting the valves on the bottom of the stroke but how would the valves come that far out of alignment so quickly?
3. Valve clearance is unknown,, previous to the ticking it was adjusted to be spot on and ran great., then this all of the sudden.
Could it be a loose tchain? it doesnt feel particularly loose on the sprocket and there isnt a ton of play but is there the possiblity of a stretched link? Its just frustrating how it developed the tick so suddenly. Will change oil and keep you posted as well as adjust valvs asap, perhaps my oil pump has gone or something? Really just dont know where to start and cant afford to take it in right now.

OK.  I'm trying to put together the order of events and I'm a little bit confused.  Let me see if I got this right:
0.  No ticking.
1.  You changed oil and adjusted the carb.
2.   The ticking happened the next time you fired it up.
3.  You corrected the timing.
4.  The ticking happened a few seconds after firing it up again.

How far out of whack was the timing?

It was a few teeth off. But yes that is the exact order of events. Looks like im screwed

motonphoto, on 25 July 2012 - 09:54 AM, said:

Are you thinking something happened to the valve train?

Don't get discouraged.  I'm going into the cases again (second time) on my Z50.  This time, it's to search for the cause of a ticking noise and a whining/whirring noise.  Troubleshooting is so much easier when the problems are obvious.  In my case, it wasn't so obvious, but I think I found the issues.  I just keep telling myself that this is a learning experience.  Don't take shortcuts and don't be in a hurry or you'll end up overlooking things or dismissing things that might be important.  I've learned that lesson more than once.

Good luck.

take your head off mate check the valves if the chain was loose and has skipped a few teeth the damage may already be done.....but if the valves look ok no marks on the piston buy a new chain see if that sorts the issue the chain shouldnt be really loose
doesnt cost anything to have a look

Edited by sharpey821, 26 July 2012 - 04:32 AM.